Automatic fluid injector

ABSTRACT

A FLUID INJECTOR INCLUDING A HOUSING HAVING A PISTON THEREIN DIVIDING THE INTERIOR OF THE HOUSING INTO FIRST AND SECOND CHAMBERS. THE HOUSING INCLUDES A FIRST PORT ADAPTED TO NECTION WITH THE FIRST CHAMBER AND A SECOND PORT ADAPTED TO COMMUNICATE WITH THE SECOND CHAMBER. A VALVE IS INCLUDED FOR PROVIDING COMMUNICATION BETWEEN THE TWO CHAMBERS AS THE PISTON MOVES FROM ITS FIRST NORMAL POSITION TO ITS SECOND DRIVEN POSITION. ADDITIONAL VALVE MEANS ARE PROVIDED IN THE HOUSING BETWEEN THE SECOND PORT AND THE SECOND CHAMBER PROVIDE COMMUNICATION THEREBETWEEN WHEN THE PISTON MOVES FROM ITS DRIVEN POSITION TO ITS FIRST NORMAL POSITION.

United States Patent [72] Inventors Lowell L. Rum";

Donald E. Bender, both of Herrin. Ill. [21] Appl. No. 805,325 [22] Filed Mar. 7, 1969 [45] Patented June 28, 1971 [73] Assignee Olin Mathieson Chemical Corporation [54) AUTOMATIC FLUID INJECTOR 9 Claims, 6 Drawing Figs.

[52] 11.8. CI 184/7 [51] Int. Cl Fl6n 23/00 [50] Field olSeareh 184/6,6 (A), 7, 7 (CH, 7 (C)-2; 222/lnquired; 137/lnquired;251/lnquired [56] References Cited UNITED STATES PATENTS 1,837,811 12/1931 Farmer 184/7 1,881,532 10/1932 Hanson 184/7 1,942,096 1/1934 1 Hallerberg... 184/7 1,967,707 7/1934 Davis 184/7 2,000,925 5/1935 Cowles 194/7 2,879,754 3/1959 Kienlin et al l84/6X FOREIGN PATENTS 515,887 1/1931 Germany 184/7 1,219,991 12/1959 France 184/7 Primary ExaminerManuel A. Antonakas Auorneys- Donald R. Motsko, H. Samuel Kieser and William W. Jones ABSTRACT: A fluid injector including a housing having a piston therein dividing the interior of the housing into first and second chambers. The housing includes a first port in connection with the first chamber and a second port adapted to communicate with the second chamber. A valve is included for providing communication between the two chambers as the piston moves from its first normal position to its second driven position. Additional valve means are provided in the housing between the second port and the second chamber to provide communication therebetween when the piston moves from its driven position to its first normal position.

PATENIEDJUN28197| v 3.581782 LOWELL LRUSSELL DONALD E. BENDER ATTORNEY INVENTORS PATENTEU JUH28 l97i INVENTORS LOWELL L. RUSSELL DONALD E. BENDER ATTORNEY AUTOMATIC FLUID INJECTOR This invention relates to an automatic, incompressible fluid injector.

More particularly, this invention relates to an incompressible fluid injector of the type adapted to inject a charge of a substantially incompressible fluid into a system in response to the application of system pressure to the injector.

The fluid injector of the present invention is especially adapted to be used as a lubricator in conjunction with an engine-starting system of the type which utilizes fluid pressure. Systems of this type usually include a source of fluid pressure such as a tank of compressed air or a breech mechanism adapted to actuate an explosive cartridge in the form ofa "low energy" propellant. The source of fluid pressure is connected to a starting assembly which may include a vane motor having movable vanes mounted in a rotor which is eccentric with the rotor casing and a drive unit. The drive unit is operably connected to the engine in such a manner that upon rotation of the vane motor due to the application of fluid pressure thereto, the drive unit will engage the engine to crank it until it becomes self-sustaining.

In systems of the above type, it is desirable to lubricate the vane motor to reduce internal motor friction, corrosion and to perform a transient residue flushing action. Accordingly, it is desirable to include in the system a lubricator which will automatically feed a predetermined amount of lubricant to the starter motor. The fluid injector of the present invention can readily be incorporated into such a system to provide this function. However, it is to be understood that the device ofthe present invention can also be used to feed any substantially in compressible fluid from a reservoir to any system upon intermittent application of system pressure to the device.

It is an object of the present invention to provide an improved injector for injecting a predetermined amount of an incompressible fluid into a system upon intermittent application of system pressure to the injector.

It is an additional object of the present invention to provide a fluid injector for injecting fluid into a system in response to system pressure which can be connected to the source of fluid to be introduced into a system and which is self-priming upon intermittent application of the system pressure.

It is a further object of this invention to provide a fluid injector which is relatively inexpensive to manufacture and effi cient in operation.

Yet another object of this invention is to provide an improved injector which can introduce a charge oflubricant into a fluid-actuated starting motor after each start.

These and other objects and advantages of the present invention will be more readily understood by reference to the following description of a preferred embodiment and to the accompanying drawings in which:

FIG. 1 is a transverse sectional view ofa preferred embodiment ofthe invention;

FIG. 2 is a cross-sectional view taken along the lines 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view taken along the lines 3-3 of FIG. 1;

FIG. 4 is a sectional view similar to FIG. 1, but showing the components positioned after application of system pressure;

FIG. 5 is a view similar to FIG. 2 showing the position of the components of the device after the decay of system pressure but before the components of the device have returned to their normal position; and

FIG. 6 is a schematic diagram showing the device of the present invention being used as a lubricator in an engine-starting system.

Referring to the drawings, the preferred embodiment of the injector 1 of the present invention includes generally a hollow housing 2 having a port 4 therein. A cap 6 closes the end ofthe housing oppositeport 4 and has a central port 8 therein. A piston 10 is mounted in the housing providing a first chamber 12 and a second chamber 14. A check valve 16 is mounted within the piston to provide communication between chambers l2 and 14 when the valve 16 is in its open position. A poppet valve 18 is mounted between port 4 and the second chamber 14 to provide communication therebetween when the valve 18 is in its open position.

More specifically, the housing 2 includes a first cylindrical internal wall 20 separated from a second cylindrical internal wall 22 of reduced diameter by a circumferentially extending shoulder 24. A valve-mounting web 26 extends transversely across the bore of the housing 2 at the inner end of port 4. As shown in FIG. 2, the valve-mounting web 26 includes a central aperture 28 formed by three longitudinally extending, circumferentially spaced arcuate portions 30 separated by three longitudinally extending, circumferentially spaced grooves 32 which extend radially outwardly from the arcuate portions 30. A bracket member 36 may be attached to the outer wall ofthe housing 2 to provide a means for attaching the device to the desired object.

The cap 6 is connected to the housing 2 by any suitable means such as screws 38. The cap 6 includes an inwardly extending, circumferential flange 40, the outer diameter of which is substantially equal to the diameter of the internal wall 20 so that the outer wall ofthe flange 20 is in engagement with the wall. An O-ring 42 of suitable material may be provided between the cap 6 and the housing 2 to prevent leakage therebetween.

The piston 10 includes a head portion 44 and an elongated cylindrical body portion 46 extending from the head portion in a direction toward poppet valve 18. The outer diameter of the body portion 46 is substantially equal to the diameter of the second cylindrical inner wall of the housing 2. An O-ring 48 is mounted in a suitable groove 50 extending about the periphery of the body portion 46 at a point where it will be in sealing engagement with the second internal wall 22. The head portion 44 includes a circular flange 52 extending axially within the housing 2 at the outer periphery ofthe head portion 44. The outer diameter of the head portion 44 as well as the flange 52 may be substantially equal to the diameter of the first cylindrical inner wall 20 or slightly smaller to provide sliding clearance therewith. An O-ring 54 may be mounted in a suitable groove 56 extending about the periphery of the head portion 44 to provide a seal between the head portion 44 and the first internal wall 20.

A bore 58 extends into the cylindrical body portion 46 from the head portion 44 to a transversely extending web portion 60 which has its bottom surface 62 spaced from the end of the body portion 46 as a distance sufficient to clear the poppet valve 18. The web portion 60 is provided with a central cylindrical aperture 64. A coil spring 66 extends between the shoulder 24 in the housing 2 and the bottom surface of the head 44 ofthe piston member 10 and urges the piston member 10 axially within the housing 2 in a direction toward the cap 6 until the upper portion of the head 44 abuts the flange 40 on the cap 6 and the piston is in its normal position.

The piston I0 is positioned within the housing 2 such that the peripheral edge of the head 44 and flange 52 along with the O-ring 54 is in sliding relationship with the inner cylindrical wall 20 and a portion of the outer surface of the cylindrical body portion is in sliding engagement with the second cylindrical inner wall 22.

The check valve 16 is mounted within the bore 58 in the piston 10. As shown in FIG. 3, the check valve 16 is essentially square in cross section except that its corners 68 are rounded in a manner such that they lie in an imaginary circle having a radius equal to the radius of the bore 58. This arrangement provides a clearance between the wall of the bore 58 and the four planar sides 70 of the check valve 16 while the corners 68 are in guiding engagement with the bore 58. The bottom surface 72 of the check valve 16 is provided with a circular groove 74 having a diameter greater than the diameter of the central aperture 64 in the web portion 60. An O-ring 76 is mounted within the groove 74 to provide sealing between the valve 16 and the valve seat 78 formed by the upper surface of the web portion 60.

A self-seating retaining ring 80 is positioned against a shoulder 82 in the bore 58 of the cylindrical body portion 46 of the piston at a point near the head 44 thereof. A suitable coil spring 84 is positioned between the retaining ring 80 and the top surface 86 of the check valve 16 to urge the check valve 16 into its closed position.

The poppet valve 18 includes an elongated, cylindrical spindle portion 88 and an enlarged circular flange portion 90 at the upper end thereof. The bottom surface of the flange 90 has a circular groove 92 therein in which is mounted an O-ring 94 of suitable sealing material. The spindle portion 88 ofthe poppet valve 18 extends through the central aperture 28 in the valve-mounting web 26 and is guided for axial movement by the three longitudinally extending, arcuate portions 30 of the aperture 28. The radius of the groove 92 of the flange 90 of the poppet valve 18 is greater than the distance from the axis of the central aperture 28 to the bottom of the grooves 32 to insure proper sealing' A self-seating retaining ring 96 is mounted on the spindle portion 88 of the poppet valve 18 adjacent its bottom end. A suitable coil spring 98 extends between the bottom surface of the web 26 and the retaining ring 96 to bias the poppet valve 18 into its closed position wherein the O-ring 94 is in sealing engagement with the upper surface of the web portion 26.

In operation, port 8 is connected to the system by means of a suitable conduit or the like and port 4 is connected to a reservoir containing the fluid which is desired to be injected into the system. in the normal position the components of the injector will be positioned as shown in FIG. 1. Spring 66 urges the piston 10 into its normal position resulting in chamber 12 having its smallest volume and chamber 14 its largest volume. The check valve 16 will be held closed by spring 84 and poppet valve 18 will be biased closed by virtue of spring 98.

Assuming that the lubricator has been primed and cavities 12 and 14, as well as the conduit from port 8 to the system is filled with the fluid, when the system is subjected to an intermittent surge of pressure, the pressure will be transmitted through the fluid in the conduit and chamber 12 and act against the top surface of the piston 10 and valve 16.

The effective area on the top of the piston 10 and check valve 16 upon which the system pressure acts is greater than the effective area'on the bottom side of the piston 10 and valve 16. Thus,. the pressure of the fluid in chamber 14 is greater than the pressure of the fluid in chamber 12. Actually, the pressure of the fluid in chamber 12 is substantially equal to the downward force exerted by the piston 10 and valve 16 minus the force of the spring 58 tending to urge the piston into its normal position all divided by the effective area of the bottom side of piston 10 and valve 16. If there is no port between the two chambers 12 and 14, the force acting on the bottom of the piston 10 would be equal to the force acting on the top of piston 10 and the piston would remain stationary. However, due to the fact that the pressure in chamber 14 is greater than the pressure in chamber 12, the force acting through aperture 56 on the check valve 16 is greater than the combined force on the top of check valve 16 due to the fluid acting on its upper surface and the spring 74. Accordingly, the check valve 16 opens permitting fluid to flow from chamber 14 to chamber 12 as the piston moves downwardly into its driven position as shown in H6. 4. In addition, the high pressure in chamber 14 also acts against the upper surface of poppet valve 18 and tends to close it tighter.

As the pressure surge in the system decays, the pressure of the fluid in chamber 12 will reach a point low enough that the piston spring 58 will begin returning the piston 10 to its original normal position. As shown in FIG. 5, as the piston moves upwardly within the housing 2, the combined force of the spring 84 and pressure of the fluid in chamber 12 will cause check valve 16 to close. Concurrently, as the piston 10 moves upwardly, a vacuum is created in chamber 14 since the fluid in chamber 14 has been exhausted. As the pressure of the fluid in the reservoir is at atmospheric pressure, because of the difference between the pressure of the fluid in port 4 and the pressure of chamber 14, the poppet valve 18 will open and the fluid will flow into chamber 14 so that when the piston hasv returned to its normal position chamber 14 will again be substantially filled with fluid. When chamber 14 is filled with fluid, the pressure in port 4 and chamber 14 will be equalized and spring 98 will close poppet valve 18.

Also, as the piston 10 moves from its drive position to its normal position, it will force into the system an amount of fluid which has flowed to chamber 12 from chamber 14 during its downward movement. This action will occur every time the system is subjected to a pressure surge resulting in a charge of fluid being injected into the system after each pressure surge. The difference in volume of chamber 14 when the piston is in the normal position and the volume of the chamber 14 when the piston is in its driven position determines the amount of fluid which will be injected into the system each time.

Although the above-described operation was made with the assumption that the injector l was primed, one particular feature of the present invention is the fact that the injector 1 can be automatically primed by subjecting it to a series of system pressure surges after it has been attached to the fluid reservoir. When the injector 1 is first attached to the system and to the reservoir, both chambers 12 and 14 will contain air. When the injector 1 is subjected to the first pressure surge, the piston 10 will move downwardly as explained above. Although air is somewhat compressible, the high volume ratio of chamber 14 (volume of chamber 14 with the piston 10 in the normal position divided by the volume in chamber 14 with the piston in its driven position) will permit the air to open the check valve 16 and to flow out against the actuating back pressure. Thus, when the piston moves from its driven position to its normal upward position, poppet valve 18 will open permitting fluid to flow into the lower chamber 14. This operation is continued until all the air has been exhausted in chambers 14 and 12 as well as in the conduit leading from port 8 to the system and such chambers and conduits filled with fluid.

By way of an example, one particular application of the injector of the present invention is in connection with a starting system which includes a starter assembly which is operated by fluid pressure to provide initial cranking of an engine. Such a system is shown schematically in FIG. 6.

The starter assembly 100 of the system is of the type which can be driven by pressurized air or gas generated by the combustion of a solid propellant cartridge. The assembly 100 includes a vane motor 101 of the type having movable vanes mounted in a rotor which is eccentric with a rotor casing. The fluid pressure rotates the rotor which in turn drives a drive unit 103 having a pinion gear 105 adapted to engage a gear 107 attached to an engine to provide initial cranking.

The air-starting portion of the system may comprise an air receiver or reservoir 102 which is provided with an inlet conduit 104 which may be connected to a suitable compressor to charge the reservoir 102 to a pressure in the range of from about lOO to about l50 p.s.i. The inlet conduit 104 is usually provided with a one-way check valve 106 to permit flow into the reservoir 102 and prohibit flow in the opposite direction.

A quick-acting, on-off, high-capacity valve 108 has its inlet port connected to the outlet of the air reservoir 102 and its outlet port connected to the main air conduit 110. The valve 108 may be ofthe type which can be actuated manually, pneumatically through an air pilot system, or electrically. In the case shown in FIG. 6, an actuation switch 112 is connected by suitable wiring 114 to the valve 108 and also to a source of electrical power (not shown) whereby valve 108 can be actuated from a remote location.

The cartridge portion of the starting system comprises a cartridge-receiving chamber 116 provided with a high-pressure safety disc 118 of a type well known in the art to let the gas escape in the event of overpressurization in the high-pressure section. The cartridge-receiving chamber 116 also includes a removable breech closure 120 containing a suitable firing mechanism (not shown) capable of igniting a cartridge assembly 122. The firing mechanism may include a firing pin which is electrically operated by virtue of an actuation switch 124 connected to the firing mechanism by suitable wiring 126 and to a source of electrical power (not shown).

The cartridge assembly may be in the form of a packaged unit including a low-energy solid propellant and an ignition device contained within a hermetically sealed metal container. A conventional primer may be provided for igniting the ignition device which in turn ignites the solid propellant.

A nozzle 128 is provided adjacent the end of the cartridge receiving chamber 116 to reduce the pressure of the gases as they enter the hot gas conduit 130. A low-pressure safety disc 132 is positioned in the hot gas conduit 130 immediately downstream of the nozzle 128 to prevent overpressurization in this section of the system.

The main air conduit 110 and the hot gas conduit 130 join together at a T-shaped connection 134 downstream of the inlet of the starter assembly 100. The main air conduit 110 is provided with a check valve 138 downstream of the connection 134 to prevent gas generated by the cartridge from flowing up to the air valve 108. The outlet of connection 134 is connected to the inlet 136 of the starter assembly 100 by any suitable means as indicated schematically by numeral 140.

A fluid injector 1 such as described above and shown in FIGS. 1-5 is incorporated into the starting system to inject lubricant into the starter assembly 100. The injector 1 has its outlet port 8 connected to the inlet 136 ofthe assembly 100 by means of a suitable conduit 142. Port 4 ofthe injector l is con nected to a lubricant reservoir 144 by means of suitable conduit 146. The conduit 146 is usually connected to the bottom of the lubricant reservoir 144 to insure a supply of lubricant. The reservoir 144 should be vented to the atmosphere by means ofa vent cap 148 or the like to insure that the lubricant will be under at least atmospheric pressure. Although as shown in FIG. 6, the conduit 142 from the injector l is con nected directly to the inlet 136 of the starter assembly 100, in a dual type of system such as shown in FIG. 6, conduit 142 may be connected to the system anywhere between the con nection 134 of the inlet 136.

After the injector 1 has been primed as explained above by repeated surges of pressure, usually by utilizing the air portion of the system, the injector will function to charge the starter assembly 100 with a predetermined quantity oflubricant after each start, whether that start be by virtue of the actuation of the cartridge assembly 122, or by virtue of air from the air reservoir 102. Upon each start, the injector will function as described above so that after a given start a charge of lubricant will be deposited in the system at a point where conduit 142 is attached. On the next start, the lubricant which was deposited after the previous start will be dispensed throughout the rotor section of the vane motor and a new charge of lubricant will be deposited in the system.

We claim:

1. A fluid injector comprising housing means having first and second ports therein, piston means mounted in said housing for movement between a first normal position and a second driven position, said piston means dividing said housing means into first and second chambers, said first port communicating with said first chamber and said second port communicating with said second chamber, means biasing said piston toward its normal position, first valve means in said piston for providing communication between said first and second chambers as said piston means moves from its first position to its second position and preventing communication between said first and second chambers when said piston means moves from its second position to its first position, second valve means between said second port and said second chamber for providing communication between said second port and said second chamber as said piston moves from its second position to its first position and preventing communication between said second port and said second chamber as said piston moves from said first position to said second position.

2. A fluid injector to inject fluid into a system in response to a surge of system pressure, said injector comprising housing means, first port means in said housing for connecting the interior of said housing means to said system, second port means in said housing for connecting the interior of said housing to a source of fluid to be injected, piston means mounted in said housing for movement between a first normal position and a second driven position when subjected to a surge of system pressure, said piston means dividing the interior of said housing into first and second chambers, the first of said chambers communicating with said first port and the second of said chambers communicating with said second port, means biasing said piston toward its normal position, first valve means for providing communication between said first and second chambers upon movement of said piston from said first position to said second position and preventing communication therebetween when said piston moves from said second position to said first position, and second valve means between said second chamber and said second port for providing communication therebetween as said piston means moves from said second position to said first position and preventing communication therebetween when said piston means moves from said first position to said second position.

3. The fluid injector of claim 2 wherein the effective area of the piston means upon which the pressure in the first chamber acts is greater than the effective area of the piston means upon which the pressure in the second chamber acts.

4. The fluid injector of claim 3 wherein said piston means includes a head portion and a reduced, elongated body portion, said housing including a first interior wall portion and a second reduced interior wall portion, and means on said head portion in sliding sealing engagement with said first wall portion and means on said body portion in sliding sealing engagement with said reduced wall portion.

5. The fluid injector of claim 4 wherein said piston means includes a bore extending from said head portion to a web extending across said body portion adjacent the end thereof, said web having an aperture therethrough, said first valve means comprising a valve member mounted in said bore and having a reduced, cross-sectional area with respect thereto, said valve having a surface for engaging said web to close said aperture, and spring means urging said valve against said web.

6. The fluid injector of claim 4 further including a web extending across the interior of said housing adjacent said second port, an aperture therein defined by a plurality of circumferentially spaced guiding surfaces and a plurality of axially extending grooves extending outwardly from said guiding surfaces, said second valve means comprising a poppet valve having a spindle extending through said aperture in said housing web in guiding engagement with said guiding surfaces and an enlarged flange positioned in said second chamber for engaging said housing web to close said aperture, and spring means urging said check valve into a position wherein said flange engages said housing web.

7. The fluid injector of claim 6 wherein said piston means includes a bore extending from said head portion to a Web extending across said body portion adjacent the end thereof, said web having an aperture therethrough, said first valve means comprising a valve member mounted in said bore and having a reduced cross-sectional area with respect thereto, said valve having a surface for engaging said web to close said aperture, and spring means urging said valve against said web.

8. The fluid injector of claim 2 wherein each of said valve means includes means biasing the valve into its closed position.

9. An engine-starting system comprising a fluid-actuated vane motor having an inlet, a rotor casing, a rotor mounted eccentrically with respect to said rotor casing and vanes movably mounted in a radial direction in said rotor, fluid producing means, means connecting said fluid-producing means to said inlet, lubricator means, and means connecting a first port in said lubricator means to said vane motor at a point prior to the point where said fluid from said fluid-producing means enters tion under pressure from said fluid wherein said first chamber l increases in volume and said second chamber is reduced in volume, valve means between said first and second chambers for providing communication between said chambers upon movement of said piston from said first to said second position, and valve means between said second chamber and said second port for providing communication therebetween as said piston moves from said second position to said first posillOll. 

